Cleaning Model Railway Track

Cleaning Model Railway Track

In January 1998, an enquiry from a member of the public on the subject of “Relco” and similar electronic track cleaners sparked (no pun intended) a lively debate on the subject of keeping model railway track clean. This is a digest of that discussion.

What is the dirt which gets onto model railway track?

Chris Dadson explained that there are five sorts of dirt:-

1. moist - electrically conductive
2. moist - electrically non-conductive
3. dry - electrically conductive
4. dry - electrically non-conductive
5. electro plating film (resulting from current flow through two dissimilar metals)

The quantity and type of dirt or crud that settles on the track will depend upon your local environment (temperature, humidity, air flow, etc.).

How does an electronic rail cleaner work?

(Chris Dadson again) Various electrical track cleaning systems (including Relco) produce an output of between 150 and 250 Volts AC in the frequency range 50 - 200 kHz. When the track cleaning system detects dirt (i.e. electrically detects an open circuit) the unit produces an AC output and superimpose it onto the track. This AC high voltage causes an arc between the track and wheels as the resulting current bridges the high resistance gap caused by the crud. This high temperature arc collapses (i.e. incinerates) the ‘dry’ crud or dirt, and evaporates the ‘moist’ crud or dirt - but in neither case will it remove it entirely. Most crud is blown off as black particles by the arcing onto the surrounding track ballast, but the process will always leave some resulting residue on the rails. How much depends entirely upon the quantity and type of dirt or crud there in the first place.

Does a Relco really clean the track?

(Still Chris Dadson) The Relco process is an ever-increasing circle, albeit a very slow process. The track cleaning system in removing the crud it deposited previously will leave yet a further amount of dirt. Constant use of these cleaning systems masks this constant build up as high frequency AC currents can penetrate through dirt far more easily than DC currents. This can easily be proven. If anyone has operated a layout using one of these systems for several months without any other form of track cleaning, try reverting back to conventional 12 volt DC operation and see how reliably the locos run particularly at slow speed.

Relco and other similar systems do tend to minimise the build up of the electro plated film caused by current flow through two dissimilar metals. Electro plating is a direct action of DC and is thus more or less avoided using AC systems. An important point to note is that this electro plated layer can only effectively be removed by conventional abrasive track cleaning.

What Voltage does a Relco produce?

Chris Gardner observed that a Relco can sometimes give a mild electric shock through the rails, but Chris Dadson explained that the high voltages used by these systems present no danger to the majority of people due to the diminutive current. The actual voltage is believed to be in the order of 150-200 volts.

Radio Intereference and other side effects

Chris Dadson spoke with authority on this subject as he had once been a Radio Interference Investigator.

These track cleaning systems are potentially dangerous devices as a cause of RFI, and will undoubtedly contravene the latest mandatory EMC Regulations. David Overall had mentioned the “sparks” effect and Chris explained that the track and associated wiring become an effective and reasonably efficient radio aerial system. Admittedly the radiation from the track wiring can be minimised by following a few simple guidelines, but there is absolutely no way of preventing those sparks and the track radiating radio noise up to a few hundred MHz right across the radio spectrum (remember that ‘spark’ transmitters were the first generation radio transmitters many years ago). Not only can this radiation cause interference to neighbours' radios and TV's, but can also interfere with sensitive communication radio receivers several miles away. Putting the EMC Regulations aside, the UK’s 1949 Wireless Telegraphy Act (+ amendments) empowers Radio Interference Investigators with extreme authority (comparable to the police and the VAT man) to enter premises, etc. Cause interference to any military, maritime, aviation or emergency services radio system and the offending track cleaner will be “seized” by the Investigator with no right of appeal.

Stern words, so be warned!

SEmG Members’ experiences

Some members loved them, some hated them.

Chris Gardner said he had had good and some bad experiences with them, and used them for years on a OO layout, running proprietary locos by Hornby, Lima and Bachmann. He was sure they reduced the amount of manual track cleaning he had to do. In N gauge, however, he had experienced engine burnouts and believed these were caused by a combination of feedback control and electronic track cleaning. Chris Dadson, however, said there was no evidence to suggest that they damage motors, including the coreless variety (Portescap, etc). However, these systems are guaranteed to destroy or corrupt any nearby electronic microprocessors (particularly if electrically connected to a common return path) unless efficient electrical filtering arrangements are included.

David Overall’s do seem to work a bit, but he still uses his Peco track rubber if the track hasn't been used for a while. He also pointed out the useful side effect is that if a loco derails or hits a dead spot, the light for that track lights permanently so you know what’s happening. He also recommended purchasers to compare prices as they vary a lot.

Dave Harris, an experience exhibitor told us that on his club’s Alreford 2mm layout they have used a HF track cleaner for some 60 exhibitions (some 100 + show operating days). However, rag and spirit is used to clean the track before sessions, sometimes twice a day. After a while you need to clean the rails as even the HF can't cope. The wheels of the locomotives also get very dirty and need regular cleaning. When the high frequency is off by mistake, he certainly notices a loss of smooth slow speed shunting operation, but on the mainline operation, he doesn’t think he can tell. On balance he believes an electronic track cleaner gives a slightly longer run with a slightly better low speed performance, before the rails and pickup wheels need cleaning.

Martin Ward recommends the Relco, commenting that the advantage is its a non-destructive cleaner (not like track rubbers etc.) so the wheel’s surfaces are not pitted. It also cleans all those contacts you can't reach, and it can markedly improve performance of all locos.

Tony Cane was quite direct. “They do not actully clean the track !!!!” He went on to explain that there has to be an interruption of current for the unit to have any effect. Thus they only keep trains going when they would otherwise have stopped, due to the track being too dirty. It does keep things moving smoothly for longer between track cleans but does not remove the need to clean the track.

Tony has always used them on his layouts, as any assistance to smooth running is welcome. But in my opinion they come a poor third to feedback controllers and pickups on every wheel on the locomotive. On point they have in their favour is that it is not only the track to wheel contact that can be improved, it will also act on the wheel to pickup connection as well. The system is also less effective on large layouts as capacitance effect from wiring and the track tend to load the output. He had, however, seen no evidence that locomotive wheels became pitted. He also reminded us that if on board lighting, deriving power from the track, or a resistor load is included across the wheels, in say a brake van, is used, it will prevent any cleaning action taking place. All these will be seen as a load by the track cleaner.

Roger Stanford was not particularly impressed. He had an H&M Relco which never seemed to do very much, except give off sparks at the loco wheels and his fingers when using a track rubber with power on. Possibly this was because he was using steel rail. The layout was in a room outside and he lives 50 metres from the sea with strong Wellington winds blowing salt spray around.

Since he has changed to Nickel Silver track the only cleaning he does is with a track rubber every now and again. A friend of his with a large layout, 30' x 15', used to onlyclean the track once a year but since the layout has gone into a purpose built shed there is much more dust etc around and he needs to clean more often, when he does he uses balsa wood and for tough spots emery paper.

Compatibility with different types of controller

Andrew Fanner explained that Relcos do not go well with sophisticated pulse controlled power supplies, as they can interfere with the pulses.

Chris Gardner reminded the group that they do not work with feedback controllers.

Mike Watts, who admitted limited technical knowledge in this matter, picked up the theme of damage to motors. He understands that pulsed controllers cause a form of vibration, which may be undetectable to the user, but causes the armature to vibrate in the bearings. For a can motor, this will definitely shorten the life considerably. I have heard, and read, that you can expect a running life of 300+ hours for the typical Escap motor in a Portescap. That may not seem much, but is much longer than most of us use them for. Pulsed power can reduce this to as low as 50 hours. The bearings disintegrate and the thing sort of implodes!

David Lord says that really slow smooth running is not possible with the relco because every time dirt is encountered, the power is interrupted while the dirt is burnt away, resulting in hesitant slow running of the locomotive. Once up to speed, this would not be noticeable, but smooth starts and stops are not conducive to dirty track and use of the relco or similar. His conclusion was that clean track in the first place is the only answer coupled with many pickups on as many wheels as is practicable.

Alternative methods of cleaning rails

Chris Dadson quoted from recent correspondence in the MERG mailing list. This had revealed the use of a small block of balsa wood. Apparently it has good cleaning powers and doesn't deposit any particles of abrasive along the track.

Martin Ward ventured to ask about the Hornby style of track cleaner which is wagon mounted, and drags a felt pad, soaked with spirit, along the rails. Immediately came the "thumbs down from David Overall, although he seemed to be talking about a later version using springs and an abrasive pad. “A load of rubbish for claning the rails.” There are two 'skis' which have self-adhesive abrasive strips on them. The skis are spring-loaded to exert pressure on the rails. The problem is with my coach is that it's too lightso the skis don't exert enogh pressure on the rails. I adjusted the internal springs, which then meant the skis lifted the wheels off the track....

I removed the skis and just run it with my breakdown crane. That's why I own a Peco track rubber and a Gaugemaster HF track cleaner! The Gaugemaster by the way has two units in it, but it only has one input for the 16VAC,and it does make a difference, although LIMA wheels seem to dirty up quicker than Hornby ones, could it be the metal used?

Chris Gardner has used an Orbit rail cleaner in N gauge. This is a motor driven vibrating pad made of Peco track rubber. In N gauge it’s mounted in a coach which makes a very heavy load for a loco. In 4mm it is loco-mounted (usually in a Lima diesel) and probably works a lot better, though no-one has yet described their experiences with it.

Also mentioned was a large permanent exhibition layout which uses a waited piece of hardboard, rough side down, dragged by a loco.

Modellers should note that abrasive cleaners should not be used on steel rail as it will destroy the thin protective coat which is there to prevent the rails from rusting.

Cliff Hutton weighed in with a different thought. A friend of his advanced an"anti-abrasive cleaner" argument some years back. He argued that linear track cleaning with abrasives (i.e. emery, wet & dry paper, commercial "rubbers" etc) produced 'millions' of tiny scratches which vastly increased the surface area of the rail giving rise to more corrosion. He favoured a piece of denim folded over the end of a strip of wood (about the size of the old fashioned wooden ruler) and secured with a rubber band. Then a few drops of "rail-cleaner" and 'push-pull' along the rails. BUT watch out for point blades etc, the fabric is prone to catching on "little sharp bits". Another alarming sight is to look at wagon and coach wheels occasionally and find that they actually have "dirt tyres". So in a way they are track cleaning for you. An hour spent cleaning off this grunge is worth it I think.

No-one mentioned proprietary chemical rail cleaners; there are a number. One, manufactured by Carr's, is called "Railclean".

This digest was edited by Chris Gardner

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